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<table width="100%" summary="page for TwinsLungs"><tr><td>TwinsLungs</td><td style="text-align: right;">R Documentation</td></tr></table>

<h2>TwinsLungs</h2>

<h3>Description</h3>

<p>Comparing lung function for twins between rural and urban environments 
</p>


<h3>Format</h3>

<p>A dataset with 14 observations on the following 3 variables.
</p>

<table summary="Rd table">
<tr>
 <td style="text-align: right;">
    <code>Pair</code></td><td style="text-align: left;"> Code for the twin pair: <code>A</code> - <code>G</code></td>
</tr>
<tr>
 <td style="text-align: right;">
    <code>Environ</code></td><td style="text-align: left;"> Living environment:  <code>Rural</code> or <code>Urban</code></td>
</tr>
<tr>
 <td style="text-align: right;">
    <code>Percent</code></td><td style="text-align: left;"> Percentage of radioactivity remaining in lungs</td>
</tr>
<tr>
 <td style="text-align: right;">
  </td>
</tr>

</table>



<h3>Details</h3>

<p>This dataset is from a study to compare the effect of living environment (rural or urban) on human lung function,
where the researchers were able to locate seven pairs of twins with one twin in each pair living
in the country, the other in a city. To measure lung function, twins inhaled  an aerosol of radioactive Teflon particles.   By 
measuring the  level of radioactivity immediately  and  then  again  after  an hour,  the  scientists  could 
measure the  rate  of &ldquo;tracheobronchial clearance.&quot;   The  percentage  of radioactivity remaining  
in the  lungs after  an hour  told  how quickly subjects'  lungs cleared the  inhaled  particles.   
</p>


<h3>Source</h3>

<p>&ldquo;Urban factor and tracheobronchial clearance&quot; by Per Camner and Klas Philipson in Archives of Environmental
Health, V. 27 (1973), page 82. Data can be found in Introduction to Mathematical Statistics and its Applications,
2nd Edition by Richard J. Larson and Morris L. Marx. Englewood Cliffs, NJ: Prentice Hall, p. 548.
</p>


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